Add a static method decode to StringDecoder

sdk/lib/io/string_transformer.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of dart.io;
 
 /**
  * String encodings.
  */
 class Encoding {
@@ skipping 73 matching lines @@
  * Stream transformer that can decode a stream of bytes into a stream of
  * strings using [encoding].
  *
  * Invalid or forbidden byte-sequences will not produce errors, but will instead
  * insert [replacementChar] in the decoded strings.
  */
 class StringDecoder implements StreamTransformer<List<int>, String> {
   var _decoder;
 
   /**
+   * Decodes a stream of bytes into a `String` with an optional
+   * [encoding] and [replacementChar].
+   *
+   * The default value for [encoding] is [Encoding.UTF_8].
+   *
+   * The default value for [replacementChar] is code point U+FFFD.
+   *
+   * Completes with the decoded `String` when the stream is done.
+   */
+  static Future<String> decode(Stream<List<int>> stream,
+                               [Encoding encoding = Encoding.UTF_8,
+                                int replacementChar]) {

[Anders Johnsen, 2013/06/24 12:57:16]

Type in replacement char?

[Søren Gjesse, 2013/06/24 13:18:16]

Done.

+    return stream
+        .transform(new StringDecoder(encoding, replacementChar ))

[Anders Johnsen, 2013/06/24 12:57:16]

Extra space at end.

[Søren Gjesse, 2013/06/24 13:18:16]

Done.

+        .fold(

[Anders Johnsen, 2013/06/24 12:57:16]

Why not join, and an optional separator?

[Søren Gjesse, 2013/06/24 13:18:16]

There is no join on streams.

+            new StringBuffer(),
+            (prev, data) => prev..write(data))
+        .then((sb) => sb.toString());
+  }
+
+  /**
    * Create a new [StringDecoder] with an optional [encoding] and
    * [replacementChar].
+   *
+   * The default value for [encoding] is [Encoding.UTF_8].
+   *
+   * The default value for [replacementChar] is code point U+FFFD.
    */
   StringDecoder([Encoding encoding = Encoding.UTF_8, int replacementChar]) {
     switch (encoding) {
       case Encoding.UTF_8:
         if (replacementChar == null) {
           replacementChar = UNICODE_REPLACEMENT_CHARACTER_CODEPOINT;
         }
         _decoder = new Utf8DecoderTransformer(replacementChar);
         break;
       case Encoding.ASCII:
@@ skipping 279 matching lines @@
 
 // Utility class for decoding Windows current code page data delivered
 // as a stream of bytes.
 class _WindowsCodePageDecoder extends StreamEventTransformer<List<int>, String> {
   void handleData(List<int> data, EventSink<String> sink) {
     sink.add(_decodeBytes(data));
   }
 
   external static String _decodeBytes(List<int> bytes);
 }